Prevalence and risk factors for nasal carriage of Staphylococcus aureus in children attending anganwaries (preschools) in Ujjain, India

BACKGROUND: Children with nasal carriage of S. aureus play an important role in community spread of S. aureus and methicillin-resistant S. aureus (MRSA). Screening the nasal carriage isolates of S. aureus for antibiotic resistance patterns will provide guidelines for empiric therapy of community-acquired infections. The aim of the present study was to determine the prevalence of S. aureus and MRSA and it’s in vitro antibiotic susceptibility pattern among children in anganwaries (preschools) of Ujjain city India. This work is an extension to our previous publication in BMC Pediatrics (http://www.biomedcentral.com/1471-2431/10/100). METHODS: A prospective study was done among children aged 1 to 6 years of age attending 100 anganwaries chosen purposely for the study to evenly cover the city. From each anganwari 10 children were randomly selected for nasal swabbing. Children having pyoderma were not included. Information on risk factors for nasal colonization was collected using a pre-tested questionnaire. Swabs from anterior nares were plated on 5% sheep blood agar. Antibiotic susceptibility tests were performed using Kirby-Bauer’s disc diffusion method according to performance standards of Clinical and Laboratory Standard Institute guidelines. RESULTS: A total of 1002 children were included in the study. The prevalence of S. aureus nasal carriage was 35% (95% confidence interval CI 32.07 to 37.98) and that of MRSA nasal carriage was 29% (95% CI 24.28 to 33.88). The factors that were independently associated with nasal carriage of S. aureus were: “age-group” i.e. as the age increased beyond the age of 2 years the OR of nasal carriage decreased, “family size of more than 10 members” OR 2.59 (95% CI 1.53-4.37; P < 0.001), and protein energy malnutrition Grade 3 or 4 (OR 1.40, 95% CI 1.04-1.90; P = 0.026). The resistance pattern of S. aureus and MRSA showed resistance not only to single antibiotic class but co-resistance and multi-drug resistance was also common. CONCLUSIONS: The high rates of nasal carriage of S. aureus and MRSA and presence of resistance to commonly used antibiotics are disturbing. Antibiotic stewardship programmes that promote judicious use of antibiotic along with strategies to prevent community spread of S. aureus are urgently needed.